Persistent smoking is a major cause of fatal disease. Despite this, many smokers relapse back to smoking shortly after making a quit attempt. These individuals may possess affective characteristics that leave them especially vulnerable to relapse. Anhedonia-an affective dimension indicative of inability to experience pleasure-may be such a characteristic. Evidence suggests that anhedonia is associated with relapse risk. However, research on the mechanisms linking anhedonia and smoking has been limited, leaving little data to guide the development of treatments that mitigate anhedonia's effect on relapse risk. Accordingly, a laboratory experiment is proposed to test hypotheses derived from an "appetitive- processing" model of anhedonia and smoking. This model purports that individuals with higher anhedonia have pre-existing deficits in reward processing, which heightens their sensitivity to the effects of acute tobacco deprivation on changes in appetitive motivational drives. Thus, when high-anhedonia individuals quit smoking, they may experience marked changes in appetitive motivation, which in turn distort the relative reward value of reinitiating smoking versus maintaining abstinence and pursuing alternate reinforcers. In this study, current smokers (N=128;>10 cig/day) will complete a baseline assessment followed by two counterbalanced experimental sessions, one in which they will have smoked ad lib and one in which they will have abstained from smoking for 12 hours. At both experimental sessions, participants will complete: (a) self-report measures of affect and cigarette craving;(b) computerized tasks that assess the motivational salience of reward-related, smoking-related, and aversive stimuli;and (c) a relapse analogue task that assesses the relative reward value of initiating smoking by measuring the extent to which participants choose to initiate smoking versus delay smoking for money. The primary aims are to test the hypotheses that smokers with higher baseline anhedonia will exhibit greater deprivation-induced: (1) deficits in the incentive properties of nonpharmacological rewards (exhibited by reductions in positive affect and the motivational salience of non-drug reinforcers);(2) increases in the incentive properties of smoking (exhibited by increases in cigarette craving and the motivational salience of smoking);(3) increases in the relative reward value of initiating smoking vs. delaying smoking for money. If successful, this study will generate essential information on the motivational mechanisms through which anhedonia increases relapse vulnerability. These data could be used to develop more effective treatments that mitigate anhedonia's influence on early relapse risk. Given the detrimental health effects of persistent smoking and the difficulty in quitting associated with anhedonia, such information could be of significant value to efforts to improve public health. PUBLIC HEALTH RELEVANCE: This study will help determine the reasons why people who have the psychological trait of anhedonia (i.e., the tendency to not enjoy pleasurable activities) are less successful when trying to quit smoking cigarettes. Uncovering these reasons could lead to the development of more effective smoking cessation treatments that prevent people from relapsing back to smoking after a quit attempt. Because of the enormous health costs associated with persistent smoking, such information could be of significant value to efforts to improve public health.